import React, { useReducer } from 'react'

function ReducerDemo() {
    const [ count, dispatch ] = useReducer((state, action) => {
        switch (action) {
            case "add":
                return state + 1
            case "sub":
                return state - 1
            default :
                return state
        }
    },0)
    return (
        <div>
            <h2>现在的分数是: { count } </h2>
            <button onClick = {()=>dispatch("add")} > add </button>
            <button onClick = {()=>dispatch("sub") } > reducer </button>
        </div>
    )
}

export default ReducerDemo